Bubkitt s



B. S. LACY.

PROCESS 0F PHOTOCHEMICAL CHLORJNATION. APPLICATION FILED APR. 19, |917.

1,308 ,-7 60. Patented July 8, 1919.

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izlzl ||||||||||llllllllll||||||||||||||||| -UNITED STATES PATENT OFFICE.

BURRITT S. LACY, F SEWAREN, NEW JERSEY, ASSIGNOR TO THE ROESSLER y HASSLACHER CHEMICAL COMPANY, 0F NEW YORK, N. Y., A CORPORATION l0F NEW Yom;

To all whom 'it may concern:-

Be it known that I, BURRITT'S. LACY,

, chlorin and 'water are charged into the 'rea citizen of the UnitedStates of America, and a-'resident of Sewaren, county of Middlesex, State of New Jersey, h-ave invented certain new and useful Improvements in Processes of Ihotochemical Chlorination,

of which the followingis a specification.

The invention`- relates to the chlorination of organic substances under the influence of j light, and the objeetvof the invention is to simplify the operation and' to prevent the losses of material which tend to occur ac .cord'ing to the methods hitherto used..

i The methods of photochemicall chlorination of substances are ordinarily carried on either in the vaporor in the liquid phase; my new'process belongs to this latter type,

and for the better understanding of it yI" shall describe my invention by way of ex?l ample, yas applied to the chlorinatlon of methylene chlorid, though it may equally well Ibe applied ,to the chlorination of many othery Lorganicgl'ili'ds, such as for example, `oluol and many other similar hydrocarbons.

pentane, henzelf:

The course of reactionadepends largely on fthe'proportion of chlorin admitted to a given quantity of hydrocarbon; if the 'ref action in the example given is desired togo on essentially according' to the equation I usuall prefer to admit to a given quan-j ti-ty'of fy'rdrocarlbon a quantity of chlorin not far'from the theoretical amount accord- -ing to the above equation, though in any case the C HCls produced tends to some extent to be further chlorinated to CCl4 leaving some unreacted (l1-1201,.'

I shall describe' my invention as. 'carried on in connection with thel apparatus shown I proceed 1n 4the production of chloroform fromf methylene chlorid and'chlorin.

Suitable amounts of meth lne chlorid and action vessely l, which latter. may be constructed of a material which like enameled Specication of Letters Patent.

Application led April 19, 1917. Serial N o. 163,228.

rRooEss or rnorocHEMIcAr. oHLortIrmzrIorr.v

Patented vJ U15T 8, 1919.

steel or stoneware l2is-1`.'esistant', to the action of chlorin and hydrochloric acid. 66 i After now flushingA out the air from above the liquid, which may be accomplished by means of a current of chlorin gas passed 1n. through pipe Q9, and' ourt through pipe 10, chlorin is passed into the methylene chlorid from a suitable container 12'through the valve 2 and the pipe 3. (13 indicates a lsuitable flow gage for indicating/the rateof admission of the chlorin.) Most of the c'hlorin dissolves in the methylene chlorid, 65,

but enough usually passes through the latter and accumulates 1n the gas Space'above the water layer to lbegin to. raise the pressure inside the vessel. By means, however, of the A centrifugal stirrer il, operated-in any' suit-70 able manner, the chlorin is continuously sucked. down from the gas space above the water layer back into the methylene chlorid, so that the tendency of thel pressure to rise is in this Way counterbalanced. It' is in 75 fact an easy matter to'maintain the pressure in the reaction vessel exactly at the desired point (narnel atmospheric pressure or slightly above it) valve if this is opened too Wide, the pressure rlses above, and vii'not wide-'enough the pressure falls below atmospheric pressure,

' as indicated by the gage 11, which latter may 'be filled with concentratedsulfuricr 85 acid as shown. i

Meanwhile as the `chlorin dissolves it is in turn continuously reacting with the methylene chlorid, under the influence of 'the light Vfrom the mercury vapor quartz 90 lamp 5, which with'its glass or fused-silica I water acket 6 may be -moved up and down in the glass or fused silica, bulb tube 7, which by means of cementing or of rulo'ber u tubingA so as to make a :gas tight joint, is' 95 '.,fitted into the lbottom of the reaction vessel. The lamp 5 may be moved-up and down by any suitable means as by screw shaft 1l screw threaded to arm 15 carrying the lamp.

y means of regulating the rate of admission offchlorin through the 80 The electric terminals for the lamp are )100 shown at `16 and 17 .and the connections for the water jacket at 18 and 19 respectively. The centrifugal stirrer 4 serves to circulate the contents of the-vessel against the cooling coil 8,-supplied with water or other cool:l 106 ing liquid through, connections 20 ,and 21, by

means of which Ithe heat developed [by the chemical reaction and -by the dissolving of the HCl is absorbed. This coil may be made of a material which like stoneware, enameled steel, silver or lead, is resistant to the 'aca convenient point, for example about'lO" to 30 C.

` "When sufiici'ent chlorin has been passed in, the inlet valve 2 is closed, the vessel is opened to the air, for example by opening air vent 10, and the lamp allowed to run until there is no more chlorin left in the solution.

' and the-crude The contents of the reaction vessel are then drawn off, the two layers separated,

roduct, which may be predominantly ch oroform or predominantly carbon tetrachlorid, depending on how mu`ch chlorin is used,- purified in the usual manner; any unused methylene chlorid may be separated by distillation and again subjected to chlorination', while the acid solution which is obtained may contain 30% by weight of hydrochloric acid or even more.

`From this description of my new invention, it is obvious that it solves easily and conveniently the many diiiiculties arising from the complicated nature of the chemical reaction and the hysical phenomena; for instance the solution of the chlorin in the organic liquid, the action of the chlorin on the organic li uid, and the absorption in the water of t-he ,l-ICI produced, go on simultaneously 'in the reaction vessel, thus not only attaining extreme compatness and simplicity of operation, but also'entirely avoiding roducts whichis likelythe loss of volatile to occur when the Cl is led rate absorption system.

There are of course manypossible var iations in the details of carrying out my mvention and the practice of my process is not to be restricted to any of such details vas shown or described. For example, instead of or in addition to using a vertical centrifugalfstirrer ofv the t ing, any other suitab emeans of accomplishing the purpose of continuously removing chlorin from the gas space by dissolving the same in the liquid ,or otherwise may be usedl at the same time circulatin the liquid against the cooling surface to eep the temxpe'rature at the V,above-mentioned. range,

which is usually not .far from the ordinary room temperature, but always" is below the boiling point ofthe non-aqueous layer, i. e., of the hydrocarbon or chloro-hydrocarbon,

' to be treated. Again,"in ,the chlorination of a liquid which like pentane, is lighter than water, the illumination by means of the chemically active light, is of course directed toward the upper 'layer` while the hydro- -chloric acid produced must be dissolved in the lower layer. by means of the centrifugal .Stirrer or other suitable means.

The apparatus shown and described herein is therefore only illustrative ofv what may be used in carrying out my process which of course may be carried out by any other suitable arrangement of apparatus decontaining replaceable hydrogen and adjacent to a layer of water, acting on the1 solution thus obtained with chemically active light, and absorbing the generated hydrochloric acid in the said layer' of water.

2. The process of preparing chlorinated hydrocarbons which comprises simultaneof preparing chlorinated l ously dissolving chlorin in an organic liquid l containing replaceable hydrogen and adjacent to a layer of water, acting on the solution thus obtained with chemically active light, absorbin the generated hydrochloric acid in the sai layer of water, and maintaining the temperature below the boiling point ofthe non-aqueous layer.

3. The process of preparing chlorinated hydrocarbons, which comprises simultaneously dissolvin chlorin in an organic liquid ,containing rep accable hydrogen and adjacent toa yer .of water, acting on the solution thus obtainedwith chemicallyactive light, absorbin -the generated hydrochloric acid in the sai layer of water, maintaining the temperature below 'the boiling point of the non-aqueous layerand maintaining the pressure at approximately atmosphericpressure by reguating therate of admission of the chlorin.

4. The process of preparing chloroform and carbon-tetrachlorid, which comprises s'imultaneously dissolving chlorin in methylene chlorid adjacent to a layer of water, actin A I y chemically active light, absorbing the generated hydrochloric acid inthe said layer of water and maintaining a-temperature in the reaclon vessel of approximately 10 to 30 l 5 5. The process of preparing chloroform and carbon-tetrachlorid, which comprises silll on thesolution thus obtainedwith Water; maintaining a temperature in the 1e-v action vessel of approximately 10 to 30C mately In testimo specification.

Aand lnaintaining thepre-ssur-e at ap rol-:iH "i atmospheric pressure by regu ating .the rate of admission of the chlorin. f

ny whereof I have signed this;`

BRRITT s. LACY. 

